The goal of this research program is to study the biosynthetic pathway to the alkaloid mesembrine and related alkaloids. Investigations of this problem are directed towards (1) a study of the pathways by which phenylalanine and tyrosine are involved in the formation of the octahydroindole skeleton, and (2) the isolation and structural investigation of new alkaloids with an aim of finding structure types which will assist delineating the biosynthetic pathway to the mesembrine alkaloids.